Safety device for pipetting aids

ABSTRACT

The invention relates to a device for holding a pipette in a pipetting aid, permitting gastight insertion of the pipette into the pipetting aid without contact pressure having to be exerted by the person handling it, spreader elements ( 2 ) being cast in a soft rubber or plastic aperture bead of the pipetting aid, and it being possible for the spreader elements ( 2 ) to have their positions relative to each other changed by tensioning elements ( 3 ) in such a way that the aperture bead can be widened for the insertion of the pipette.

The invention relates to a device for holding a pipette in a pipettingaid, permitting gastight insertion of the pipette into the pipetting aidwithout contact pressure having to be exerted by the person handling it.

Pipetting aids which are known in the prior art have an essentially softplastic or rubber attachment part suitable for holding pipettes. The endpart of conventional pipettes which is intended for insertion into thepipetting aid usually has an external diameter of about 7 mm and cangenerally be inserted 1 to 2 cm into the attachment part or the neck ofthe pipetting aid. To make insertion easier, the attachment part of thepipetting aid is given a conical shape in the area of its aperture. Bypressing the end part of the pipettes against the conical aperture, theend part is pushed into the attachment part of the pipetting aid. Indoing so, the soft plastic or rubber closes tightly round the end partof the pipette.

In the case of Peläus balls and similar pipetting aids, the attachmentpart is not shaped conically. Here, an outer rubber bead is providedwhich has a slightly smaller internal diameter than the externaldiameter of the end part of the pipette. In order to introduce the endpart of the pipette into the attachment part, a pressure or contactpressure has to be overcome here to ensure the necessary gastightinsertion of the end part of the pipette into the pipetting aid. Wheninserting the pipette into the pipetting aid with pressure, it oftenhappens that the pipettes break, particularly those made of glass. Insome circumstances this can lead to serious injuries to the personhandling the pipette.

The object of the present invention is to remedy the disadvantages ofthe prior art. In particular, the aim is to make available a device forholding a pipette in a pipetting aid, with which device the risk ofinjury when inserting the pipette into the pipetting aid is reduced.

This object is achieved by the features of Claim 1. Expedientembodiments of the invention are evident from the features of claims 2to 12.

According to the invention, a device for holding a pipette in apipetting aid is provided, permitting gastight insertion of the pipetteinto the pipetting aid without contact pressure having to be exerted bythe person handling it, spreader elements being cast in a soft rubber orplastic aperture bead of the pipetting aid, and it being possible forthe spreader elements to have their positions relative to each otherchanged by means of tensioning elements in such a way that the aperturebead can be widened for the insertion of the pipette. The proposeddevice allows the operator to insert the end part of the pipette intothe attachment part of the pipetting aid without exerting anyappreciable contact pressure. In this way, breakage, especially ofpipettes made of glass, is avoided during insertion. The risk of injuryis reduced.

Illustrative embodiments of the invention are explained in greaterdetail below with reference to the drawing, in which:

FIG. 1 shows a perspective representation of a first illustrativeembodiment of the device, and

FIG. 2 shows a perspective representation of a second illustrativeembodiment of the device.

A first illustrative embodiment of the device is shown in perspectiverepresentation in FIG. 1. The device is usually disposed in the neck 11of a pipetting aid 10. The device consists of two spreader elements 2which are each connected at their first end E1 to tensioning elements 3which are designed in the form of a curved strip. The spreader elements2 each have a semicircle-shaped section 2 a. The section 2 a is cast inthe aperture bead 9 of the pipetting aid 10. The tensioning elements 3each have a slit-shaped recess 5. They are arranged in such a way thatthey bear against each other with their external diameter. In this waythe recesses 5 form a passage for a pressure equalization aperture 8,such as a hollow connection 1. The tensioning elements 3 also havethickened parts 4 serving as pressure points. In the illustrativeembodiment shown here, the tensioning elements are designed astensioning springs, which are made of spring steel.

FIG. 2 shows, in perspective representation, a further illustrativeembodiment of the device. The spreader elements 2 are each connected tothe first end E1 of a tensioning element 3. The two ends E2 of the twotensioning elements are connected to a rigid ring 6 which is cast in theneck 11 of the pipetting aid 10. The spreader elements 2 have thickenedparts 4 on their outsides and these thickened parts 4 serve as pressurepoints for pressing the spreader elements together. A further rigid ring7 is situated between the spreader elements 2 and a plane formed by thethickened parts 4, which ring 7 is likewise cast in the neck of thepipetting aid. The further ring 7 can be connected to the tensioningelements 3. The tensioning elements 3 are here made of a spring ortensioning wire.

The device functions as follows:

When pressure is exerted on the thickened parts 4, the spreader elements2 are moved apart by the tensnioning elements 3. This causes a radialwidening of the aperture bead 9 of the pipetting aid 10. Because of thiswidening, it is no longer necessary to exert pressure on the pipette inorder to insert the end part of said pipette into the pipetting aid. Inthis way, breakage, in particular of glass pipettes, is avoided duringinsertion.

List of Reference Labels

1 Hollow connection

2 Spreader element

2 a Semicircle-shaped section

3 Tensioning spring

4 Thickened part

5 Recess

6 Rigid ring

7 Further rigid ring

E1 First end of the tensioning springs

E2 Second end of the tensioning springs

What is claimed is:
 1. Pipetting aid with a device for holding apipette, permitting gastight insertion of the pipette into the pipettingaid without requiring contact pressure to be exerted by the personhandling the pipette, said device comprising spreader elements, saidspreader elements being disposed within an aperture bead of thepipetting aid, the aperture bead being made of flexible rubber orplastic, and tensioning elements for changing the position of thespreader elements so that the aperture bead is widened for the insertionof the pipette.
 2. Pipetting aid according to claim 1, wherein twospreader elements are provided.
 3. Pipetting aid according to claim 2,wherein the spreader elements have an essentially semicircle-shapedsection.
 4. Pipetting aid according to claim 1, wherein each of thespreader elements is connected in each case to a first end of thetensioning element.
 5. Pipetting aid according to claim 1, wherein thetensioning elements are made of a spring steel.
 6. Pipetting aidaccording to claim 1, wherein the tensioning elements are designed inthe form of a curved strip and are arranged so that they bear againstone another with their external radius.
 7. Pipetting aid according toclaim 6, wherein the tensioning elements have a recess.
 8. Pipetting aidaccording to claim 7, wherein a pressure equalization aperture isprovided for pressure equalization between a cavity behind the aperturebead and the pipetting aid.
 9. Pipetting aid according to claim 8,wherein the pressure equalization aperture is a hollow connectionengaging the recesses.
 10. Pipetting aid according to claim 8, whereinthe spreader elements are in each case connected at their second end toa rigid ring, said ring being disposed in a neck of the pipetting aid.11. Pipetting aid according to claim 10, wherein a further rigid ring isdisposed in the neck of the pipetting aid.